Phosphate tightly associated with a molecule, e.g., a protein, has been known since the late nineteenth century. Since then, a variety of covalent linkages of phosphate to proteins have been found. The most common involve esterification of phosphate to serine, threonine, and tyrosine with smaller amounts being linked to lysine, arginine, histidine, aspartic acid, glutamic acid, and cysteine. The occurrence of phosphorylated molecules, e.g., proteins implies the existence of one or more kinases, e.g., protein kinases, capable of phosphorylating various molecules, e.g., amino acid residues on proteins, and also of phosphatases, e.g., protein phosphatases, capable of hydrolyzing various phosphorylated molecules, e.g., phosphorylated amino acid residues on proteins.
Protein kinases and phosphatases play critical roles in the regulation of biochemical and morphological changes associated with cellular growth and division (D""Urso, G. et al. (1990) Science 250: 786-791; Birchmeier. C. et al. (1993) Bioassays 15: 185-189). They serve as growth factor receptors and signal transducers and have been implicated in cellular transformation and malignancy (Hunter, T. et al. (1992) Cell 70: 375-387; Posada, J. et al. (1992) Mol. Biol. Cell 3: 583-592; Hunter, T. et al. (1994) Cell 79: 573-582). For example, protein kinases have been shown to participate in the transmission of signals from growth-factor receptors (Sturgill, T. W. et al. (1988) Nature 344: 715-718; Gomez, N. et al. (1991) Nature 353: 170-173), control of entry of cells into mitosis (Nurse, P. (1990) Nature 344: 503-508; Maller, J. L. (1991) Curr. Opin. Cell Biol. 3: 269-275) and regulation of actin bundling (Husain-Chishti, A. et al. (1988) Nature 334: 718-721).
Protein kinases and phosphatases can be divided into different groups based on either amino acid sequence similarity or specificity for either serine/threonine or tyrosine residues. A small number of dual-specificity kinases and phosphatases have also been described. Within the broad classification, kinases and phosphatases can be further sub-divided into families whose members share a higher degree of catalytic domain amino acid sequence identity and also have similar biochemical properties. Most protein kinase and Phosphatase family members also share structural features outside the kinase and Phosphatase domain, respectively, that reflect their particular cellular roles. These include regulatory domains that control kinase or Phosphatase activity or interaction with other proteins (Hanks, S. K. et al. (1988) Science 241: 42-52).
The present invention is based, at least in part, on the discovery of novel nucleic acid molecules and polypeptides encoded by such nucleic acid molecules, referred to herein as xe2x80x9cKinasesxe2x80x9d and xe2x80x9cPhosphatasesxe2x80x9d. The Kinase and Phosphatase nucleic acid and polypeptide molecules of the present invention are useful as modulating agents in regulating a variety of cellular processes. Accordingly, in one aspect, this invention provides isolated nucleic acid molecules encoding Kinase and Phosphatase polypeptides, as well as nucleic acid fragments suitable as primers or hybridization probes for the detection of Kinase- and Phosphatase-encoding nucleic acids.
In one embodiment, a Kinase and a Phosphatase nucleic acid molecule of the invention is at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98% or more homologous to a nucleotide sequence (e.g., to the entire length of the nucleotide sequence) including SEQ ID NO:1-4, or a complement thereof.
In a preferred embodiment, the isolated nucleic acid molecule includes the nucleotide sequence shown SEQ ID NO:1-4, or a complement thereof. In another preferred embodiment, an isolated nucleic acid molecule of the invention encodes the amino acid sequence of a human Kinase or Phosphatase polypeptide.
Another embodiment of the invention features nucleic acid molecules, preferably Kinase and Phosphatase nucleic acid molecules, which specifically detect Kinase and Phosphatase nucleic acid molecules relative to nucleic acid molecules encoding non-Kinase and non-Phosphatase polypeptides. For example, in one embodiment, such a nucleic acid molecule is at least 20, 30, 40, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, or 800 nucleotides in length and hybridizes under stringent conditions to a nucleic acid molecule comprising the nucleotide sequence shown in SEQ ID NO:1 -4, or a complement thereof.
In other preferred embodiments, the nucleic acid molecule encodes a naturally occurring allelic variant of a human Kinase or Phosphatase polypeptide, wherein the nucleic acid molecule hybridizes to a nucleic acid molecule which includes SEQ ID NO:1-4 under stringent conditions.
Another embodiment of the invention provides an isolated nucleic acid molecule which is antisense to a Kinase or a Phosphatase nucleic acid molecule, e.g., the coding strand of a Kinase or a Phosphatase nucleic acid molecule.
Another aspect of the invention provides a vector comprising a Kinase or a Phosphatase nucleic acid molecule. In certain embodiments, the vector is a recombinant expression vector. In another embodiment, the invention provides a host cell containing a vector of the invention. The invention also provides a method for producing a polypeptide, preferably a Kinase or a Phosphatase polypeptide, by culturing in a suitable medium, a host cell, e.g., a mammalian host cell such as a non-human mammalian cell, of the invention containing a recombinant expression vector, such that the polypeptide is produced.
Another aspect of this invention features isolated or recombinant Kinase polypeptides and proteins. In one embodiment, the isolated polypeptide, preferably a Kinase polypeptide, is a eukaryotic protein kinase. Another aspect of this invention features isolated or recombinant Phosphatase polypeptides and proteins.
In a further embodiment, the isolated polypeptide, preferably a Kinase or a Phosphatase polypeptide, plays a role in signaling pathways associated with cellular growth, e.g., signaling pathways associated with cell cycle regulation. In another embodiment, the isolated polypeptide, preferably a Kinase or a Phosphatase polypeptide is encoded by a nucleic acid molecule having a nucleotide sequence which hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1-4.
Another embodiment of the invention features an isolated polypeptide, preferably a Kinase and a Phosphatase polypeptide, which is encoded by a nucleic acid molecule having a nucleotide sequence at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 5 90%, 95%, 98% or more homologous to a nucleotide sequence (e.g., to the entire length of the nucleotide sequence) including SEQ ID NO:1-4 or a complement thereof.
This invention further features an isolated polypeptide, preferably a Kinase and a Phosphatase polypeptide, which is encoded by a nucleic acid molecule having a nucleotide sequence which hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1-4, or a complement thereof.
In another aspect, the invention pertains to any individual Kinase or Phosphatase nucleic acid molecule from the above-identified group (SEQ ID NO:1-4), as well as any subgroups from within the above-identified group. Furthermore, the subgroups can preferably consist of at least 1, 2, 3, or more members of the group identified above. For example, the group consisting of the Kinase and Phosphatase nucleic acid molecules of SEQ ID NO:1-4 can be divided into one or more subgroups as follows: SEQ ID NO:1-2, SEQ ID NO:2-4, SEQ ID NO:3-4, and SEQ ID NO:1-3, or any combinations thereof.
The polypeptides of the present invention can be operatively linked to a non-Kinase and a non-Phosphatase polypeptide (e.g., heterologous amino acid sequences) to form fusion proteins. The invention further features antibodies, such as monoclonal or polyclonal antibodies, that specifically bind polypeptides of the invention, preferably Kinase and Phosphatase polypeptides. In addition, the Kinase and Phosphatase polypeptides, e.g, biologically active polypeptides, can be incorporated into pharmaceutical compositions, which optionally include pharmaceutically acceptable carriers.
In another aspect, the present invention provides a method for detecting the presence of a Kinase and a Phosphatase nucleic acid molecule, polypeptide or polypeptide in a biological sample by contacting the biological sample with an agent capable of detecting a Kinase and Phosphatase nucleic acid molecule, polypeptide or polypeptide such that the presence of a Kinase and a Phosphatase nucleic acid molecule, polypeptide or polypeptide is detected in the biological sample.
In another aspect, the present invention provides a method for detecting the presence of Kinase and Phosphatase activity in a biological sample by contacting the biological sample with an agent capable of detecting an indicator of Kinase and Phosphatase activity such that the presence of Kinase and Phosphatase activity is detected in the biological sample.
In another aspect, the invention provides a method for modulating Kinase and Phosphatase activity comprising contacting a cell capable of expressing Kinase and Phosphatase with an agent that modulates Kinase and Phosphatase activity such that Kinase and Phosphatase activity in the cell is modulated. In one embodiment, the agent inhibits Kinase and Phosphatase activity. In another embodiment, the agent stimulates Kinase and Phosphatase activity. In one embodiment, the agent is an antibody that specifically binds to a Kinase and Phosphatase polypeptide. In another embodiment, the agent modulates expression of Kinase and Phosphatase by modulating transcription of a Kinase and Phosphatase gene or translation of a Kinase and Phosphatase mRNA. In yet another embodiment, the agent is a nucleic acid molecule having a nucleotide sequence that is antisense to the coding strand of a Kinase or Phosphatase mRNA or a Kinase or Phosphatase gene.
In one embodiment, the methods of the present invention are used to treat a subject having a disorder characterized by aberrant Kinase or Phosphatase polypeptide or nucleic acid expression or activity by administering an agent which is a Kinase or a Phosphatase modulator to the subject. In one embodiment, the Kinase and Phosphatase modulator is a Kinase and a Phosphatase polypeptide, respectively. In another embodiment the Kinase and Phosphatase modulator is a Kinase and Phosphatase nucleic acid molecule, respectively. In yet another embodiment, the Kinase and Phosphatase modulator is a peptide, peptidomimetic, or other small molecule. In a preferred embodiment, the disorder characterized by aberrant Kinase or Phosphatase polypeptide or nucleic acid expression is a cellular growth related disorder, e.g., a proliferative disorder such as cancer.
The present invention also provides a diagnostic assay for identifying the presence or absence of a genetic alteration characterized by at least one of (i) aberrant modification or mutation of a gene encoding a Kinase or a Phosphatase polypeptide; (ii) mis-regulation of the gene; and (iii) aberrant post-translational modification of a Kinase or a Phosphatase polypeptide, wherein a wild-type form of the gene encodes a polypeptide with a Kinase or a Phosphatase activity.
In another aspect the invention provides a method for identifying a compound that binds to or modulates the activity of a Kinase or a Phosphatase polypeptide. The method includes providing an indicator composition comprising a Kinase or a Phosphatase polypeptide having Kinase or Phosphatase activity, respectively, contacting the indicator composition with a test compound, and determining the effect of the test compound on Kinase or Phosphatase activity in the indicator composition to identify a compound that modulates the activity of a Kinase or a Phosphatase polypeptide.
Other features and advantages of the invention will be apparent from the following detailed description and claims.